numpy.core.multiarray failed to import

[HTLife]

import numpy as np
import quaternion
np.quaternion(1,0,0,0)

RuntimeErrorTraceback (most recent call last)
RuntimeError: module compiled against API version 0xc but this version of numpy is 0xb


ImportErrorTraceback (most recent call last)
<ipython-input-6-9f69562c49db> in <module>()
      1 import numpy as np
----> 2 import quaternion
      3 np.quaternion(1,0,0,0)

/usr/local/lib/python2.7/dist-packages/quaternion/__init__.py in <module>()
      6 import numpy as np
      7 
----> 8 from .numpy_quaternion import (quaternion, _eps,
      9                                from_spherical_coords, from_euler_angles,
     10                                rotor_intrinsic_distance, rotor_chordal_distance,

ImportError: numpy.core.multiarray failed to import

[HTLife]

After reinstall numpy and numpy-quaternion, this issue could be resolve.

pip uninstall numpy
pip uninstall numpy-quaternion
pip install numpy numpy-quaternion

[moble]

For anyone else who finds this issue, the failed multiarray import is common across many modules that use numpy (not just this one), and is generally due to mismatched versions of libraries used to compile things — usually specifically numpy, not the module that depends on it. So the usual solution to this problem is simply

pip install --upgrade --force-reinstall numpy

Some people on Windows have apparently also reported needing to restart their computers.

[bram-ivs]

If you don't want to (or unable) upgrade numpy, you can also compile numpy-quaternion from source to avoid the binary mismatch.

pip install --no-binary ":all:" numpy-quaternion